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Showing 1 to 20 of 23 for “"boron trifluoride"”.
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Zur Oligomerisierung von 1-Decen mit ionischen Flüssigkeiten
… was reached using systems consisting of boron trifluoride and tetrafluoroborates. In this work there is shown that boron trifluoride can be immobilised and recycled in ionic liquids. Further on there is explained how to control the product distribution from geometric to Poisson-like by …
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Preparation and Properties of Azetidine-2-Ones
… In the presence of boron trifluoride etherate and toluene as solvent the rearrangement of azetidine-2-ones results in the formation of a propionamide by ring opening of the azetidinone and electrophilic substitution of the intermediate into the aromatic ring of the …
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Nuclear Magnetic Resonance Studies of Acid-Base Interactions: Part I. Proton Magnetic Resonance Studies of Hydrogen Bonding. Part Ii. J(boron-11-Fluorine-19) in Boron Trifluoride and Its Derivatives
Made available in DSpace on 2014-12-09T17:35:02Z (GMT). No. of bitstreams: 1 6503576.pdf: 4257982 bytes, checksum: ea83a01e8f7216d223d4c2ccc7555081 (MD5) Previous issue date: 1964
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Fading of carbonless copying paper
… from S-RB (2),f whereas the weaker Lewis acid boron trifluoride, did in fact retard the dye development. A coordination complex with a different ,tmax for 1absorptionwas detected with boron trifluoride and S-RB (2). The oxIdation of S-RB (2) on Fulacolor was shown to occur at two distinct …
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Photonuclear reactions near threshold
… studied by observing the emitted neutrons with a boron trifluoride counter in a tank of paraffin. From considerations regarding the shapes of the cross sections curves near threshold, evidence has been obtained which indicates that electric quadupole and magnetic dipole absorption of photons …
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Synthesis of delta-1(9)-octalinols and their analogues
… with mixtures of acetic anhydride-acetic acid-boron trifluoride proved unsuccessful. Two model compounds derived from hecogenin and incorporating the octalinol residue 1 were also prepared in the hope that the analogous ketone 2 might be obtained. This reaction, too, was unsuccessful.
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NMR studies of mixed tetrahaloborates and some related boron trihalide complexes /|nGary John Schrobilgen. -- 260 St. Catharines, Ont. : [s. n.],
… been used to study donor-acceptor complexes of boron trifluoride with several ureas, tetramethylthiourea, tetramethylselenourea, and tetramethylquanidine as well as adducts of tetramethyl- -urea with BF2Cl, BFC1 2 , and BC1 3 - A large number of mixed tetrahaloborate ions, including some of the …
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Stereospecific Syntheses from Podocarpic Acid
… methoxy acid (4) ( Scheme 1 ) . A study of the boron trifluoride rearrangements of the three epoxides (12), (13), and (14), has been made using benzene and dimethyl sulphoxide as solvents. The stereochemistry of a series of 6-bromo-7-oxo derivatives of diterpenoids possessing an aromatic ring-C …
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I. Sulfonium-Mediated Oxidative Glycosylation of Glycal Donors for the Synthesis of C(2)-Hydroxy-Beta-Glycosides. II. Hypervalent Iodine (iii)-Mediated Oxidative Glycosylation of Glycal Donors for the Synthesis of C(2)-Acyloxy-Beta-Glycosides. III. Efforts Toward the Synthesis of Immunologic Adjuvant Qs-21a(api)
… were activated with bisacyliodobenzene and boron trifluoride diethyl etherate for the synthesis of 1,2-trans -C2-acyloxy-beta-glycoside with the application to assemble non-C2-branched oligosaccharides. In the third section of this thesis, an acylated triterpene glycoside QS-21Aapi was …
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Asymmetric synthesis of novel anthracyclinones
… Stronger Lewis acids gave poorer selectivity and boron trifluoride etherate reacted slowly with (30) but with high selectivity to give the diastereomerically pure fluorotetracycle (91) in 58% yield. The presence of a β-methoxy group in the substrate leads to decreased stereoselectivity due to …
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A Study of Lewis Acid-Base Interactions: Part 1 - a Tin-119 Moessbauer and Tin-119 Nmr Study of the 1: 1 Lewis Base Adducts of Trimethyltin Chloride. Part 2 - a Calorimetric, and F(19), B(11), and H(1) Nmr Study of the Lewis Base Adducts of Boron-Trifluoride
Made available in DSpace on 2014-12-09T17:36:13Z (GMT). No. of bitstreams: 1 6910722.pdf: 5353101 bytes, checksum: 36aca5a579ee06afcbff0064c0a9f87d (MD5) Previous issue date: 1968
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Analysis and characterisation of an acylphosphine oxide photoinitiator
… (HQ)), acids (methyl sulphonic acid (MSA) and boron trifluoride dihydrate (BF3∙2H2O)) and water present in the solvent were also investigated. These studies were monitored over time using LC-UV and CE-UV methods. Mass spectrometry was employed for the first time to investigate the pathways and …
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Macrocyclic chemistry: Part I - Characterization of a mixed-valence di-iron complex and synthesis of a new poly-iron complex. Part II - Synthesis, characterization of new diphosphoester macrocyclic polyethers
… reduction of iron mono-keto-macrocycles with boron trifluoride and triethylsilane showed a coupling reaction to form a di-iron complex. A mixture of iron mono-keto-macrocycic with iron diketo-dimacrocycle showed a new species with an intense NIR absorption at 1010 nm. This intense band at 1010 …
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Dipole moments and Kerr effect of poly(n-vinylcarbazole) and its complexes with trinitrofluorenone
… and cationic catalysts (boron-trifluoride etherate and aluminium chloride). The polymers produced were characterised by molecular weight measurements and powder x-ray diffraction. The tacticity of the polymer samples was determined using proton and carbon-13 nuclear …
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Studies in ring D fragmentation of estrone
… 10)-trien, Fragmentation with the borontrifluoride diethyl ether complex resulted in formation of the undesired 3-methoxy13,17-secoestra-l ,3,5(1 0),l4-tetraen-17-nitrile. Since the 15β-trimethylsilyl group did not direct the fragmentation, the …
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Design and synthesis of rotational analogues of estradiol
… was obtained as the minor product of the boron trifluoride mediated reaction between the 14, 16-diene and methyl vinyl ketone (MVK). The major compound was formulated 16a.-acetyl-3-methoxy-17P-3'- oxobutyl-14, l 7a.-ethenoestra-1,3,5(10)-triene, on the basis of the available spectral data. …
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Oxo, imido, and nitrido compounds of osmium(VI)
… The compound reacted with boron trifluoride to form an adduct in solution and with methyltrifluoromethane sulfonate to form the methylimide, (($\eta\sp5$-C$\sb5$H$\sb5$)Os(NMe)(CH$\sb2$SiMe$\sb3$)$\sb2$) (OSO$\sb2$CF$\sb3$). The crystal structure of the silver dimer was …
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A New Synthesis of enantiopure C-3-substituted Glutamates by Utilization of Ortho Ester protected (S)-Pyroglutamic acid
… After rearrangement with boron trifluoride, the ortho ester derivatives (Acceptor=Cbz,CO2Me) were at hand and exclusively the N-Cbz derivative was converted to the corresponding alpha,beta-unsaturated lactam via a syn-elimination reaction. The formation of the …
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